In recent years it has been desired to provide photographic materials which give images having high sharpness and which can be processed rapidly (in less than 90 seconds) to facilitate accurate and rapid diagnoses in the field of medicine.
With regard to sharpness, there have been proposed methods wherein an improvement in sharpness depends on the amount of light absorbed by spectral sensitizing dyes which in large quantities are adsorbed by silver halide grains having a large specific area and a high aspect ratio (ratio of the average diameter of circles equivalent to the projected areas of grains to the thickness of grain) in an ortho-system (a system consisting of a combination of a rare earth element intensifying screen such as Gd.sub.2 O.sub.2 S with an ortho-photographic material having sensitivity in the green region). JP-A-1-126645 discloses a method for improving sharpness wherein there are used photographic materials containing dyes absorbing light in the sensitive region thereof, dyes being deposited on mordants.
However, when high sharpness (cross-over of less than 10%) is attained in these methods, a problem of residual dye occurs when processing is carried out in less than 90 seconds
A method wherein cross-over is made less than 10% by using dyes in the form of crystalline grains has recently been disclosed in EPO 276566A1. The problems of sharpness and residual dye in 90-second processing can be solved by this method. However, a problem of residual dye in 45-second processing occurs. When dyes are allowed to exist in the form of fine crystalline grains, the amount of binders will be increased. (When the amount of the binders is reduced, surface artifact is caused and the correctness of diagnoses is greatly reduced.) Further, when the amount of the binder is increased, the possibility of forming agglomerates is increased and surface damage is liable to occur. Methods for removing agglomerates with filters have been proposed to solve the problem. However, these methods have a serious problem in the handling of the photographic materials during the course of production.
Accordingly, it has been desired to provide a method wherein dyes are incorporated in dye-fixing layers without forming cryatalline grains or agglomerates.